[SystemSafety] Bicycle Helmets

[Mike Ellims]

Peter wrote:

> That's the puzzle. The value of helmets is obvious - many of us seem to
know some one
> or more whose lives have been saved - but apparently not from the numbers.

One thing that must be kept in mind when discussing bike helmets is that the
collision design speed is (if I remember correctly) only around 20 kph. Thus
if the collision speed is below that then the helmet should perform as
advertised at speeds greater than that... In particular helmets are designed
to protect you falling off the bike i.e 

"BSI Standard 6863:1987 read as follows: 
'It (the standard) specifies requirements for helmets intended for use by
pedal cyclists on ordinary roads, particularly by young riders in the 5
years to 14 years age group, but which may 
also be suitable for off the road. It is not intended for high-speed or long
distance cycling, or for riders 
taking part in competitive events. The level of protection offered is less
than that given by helmets for 
motorcycle riders and is intended to give protection in the kind of accident
in which the rider falls onto the road without other vehicles being
involved.'".

I took this from the following http://www.cyclehelmets.org/papers/c2023.pdf

An interesting article available on the same site is
http://www.cyclecraft.co.uk/digest/effectiveness.pdf which points out lots
of studies seem to have some bias and concludes that:

" It seems reasonable to expect that reductions in injuries brought about
through the wearing of cycle
helmets would be reflected in the general accident statistics in places
where helmet use has become
significant. This should particularly be the case if the more optimistic
predictions for injury reduction
are correct. However, whole population statistics from Australia, New
Zealand, the United States and
Canada show no distinguishable change in fatalities, and statistics for
London show no such change
for any severity of injury, as helmet use has increased substantially.

This suggests that the real-world performance of cycle helmets may be
falling well short of the
predictions that have been made."

Mind you I intend to keep wearing my helmet because in all but one instance
where I've come off no other vehicle was involved and off's have mostly been
at low speed; a few on iced roads, one where I forgot to loosen the straps
on my pedals before stopping and fell over; and one where the chain jammed
starting off... and I fell over. The other incident was where I was t-boned
by a car; if the oncoming traffic hadn't stopped having a brain bucket would
have made no difference.



-----Original Message-----
From: systemsafety-bounces at lists.techfak.uni-bielefeld.de
[mailto:systemsafety-bounces at lists.techfak.uni-bielefeld.de] On Behalf Of
Peter Bernard Ladkin
Sent: 15 October 2014 06:52
To: systemsafety at lists.techfak.uni-bielefeld.de
Subject: Re: [SystemSafety] Bicycle Helmets



On 2014-10-15 00:01 , David Crocker wrote:
> I have some indirect experience of the value of cycle helmets.

David's story is similar to what happened in one of the two incidents to my
friend who wrecked two helmets and her jaw, but in her case it was a
lamppost base.

That's the puzzle. The value of helmets is obvious - many of us seem to know
some one or more whose lives have been saved - but apparently not from the
numbers.

PBL

Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld,
33594 Bielefeld, Germany
Tel+msg +49 (0)521 880 7319  www.rvs.uni-bielefeld.de




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